Spark-plug.



I. P. KEPLER.

SPARK PLUG.

APPLICATION FILED 1330.10, 1908. RENEWED NOV. 28, 1909.

Patented July 12, 1910.

wwwiioz UNITED STATES PATENT ()FFTCE.

IRWIN FLOYD KEPLER, OF AKRON,

SPARK-PLUG.

Application filed December 10, 1908, Serial No. 468,866.

To all whom it may concern:

Be it known that I, IRWIN FLOYD KEPLER, a citizen of the United States,residing at Akron, in the county of Summit and State of Ohio, haveinvented certain new and useful Improvements in Spark-Plugs; and I dodeclare the following to be a full, clear, and exact description of theinvention, such as will enable others skilled in the art to which itappertains to make and use the same.

This invention relates to improvements in spark plugs.

The object of the invention is to provide a spark plug having meanswhereby a short circuit will be positively prevented under anycircumstances.

A further object is to provide a plug constructed in such manner thatthe same will not be easily broken by the contraction or expansion ofthe metallic parts surrounding the plug.

lVith these and other objects in view, the invention consists of certainnovel features of construction, combination and arrangement of parts aswill be described and particularly pointed out in the appended claims.

In the accompanying drawing, Figure l is a side view of a plugconstructed in accordance with my invention, showing an electricterminal connected therewith; Fig. 2 is a longitudinal sectional view ofthe same showing the plug arranged in place in the side of a cylinder;Fig. 3 is an outer end view of the plug and the terminal attaching cap;Fig. at is an enlarged sectional view of the inner and outer sections ofthe spring-retracted terminal fastening or cap of the plug, showingthese parts separated; Fig. 5 is a plan view of the blank from which theouter cap is formed; Fig. 6 is a longitudinal sectional view showing amodified construction of the plug.

Referring more particularly to the drawings, 1 denotes the plug, whichis con structed of porcelain or other suitable material and has formedtherethrough a centrally disposed bore, 2, in which is arranged aninsulating filling, 3, through which, and the ends of the plug, thebinding pin, 1, of the electric terminal is arranged.

The plug is provided substantially midway between its ends with anannular enlarged portion, 5, which is adapted to engage the outerenlarged portion of the nipple, 6,

Specification of Letters Patent.

Patented July 12, 1910.

Renewed November 28, 1999. Serial No. 530,004.

which holds the plug in the side of the cylinder. The enlarged portionof the plug is engaged by a bushing, 7, shaped on its inner side to fitthe enlargement and which is adapt ed to be screwed into the outer endof the nipple, as shown. The inner end of the binding pin, 4, projectsbeyond the inner end of the plug in position to co-act with the innerterminal 8 of the electric circuit to form the spark for igniting thecharge in the cylinder.

On the outer end of the plug is arranged a terminal fastening cap, 9,comprising an in ner sleeve or ferrule, 10, having formed thereon screwthreads and having its inner edge turned inwardly to provide a bearing,12, for the inner end of a coiled retracting spring, 13, which isarranged around a reduced neck portion, 1%, on the outer end of theplug. The outer end of the spring, 13, bears against the annularshoulder, 15, formed on the outer end of the plug, as shown. The outerportion of the cap com prises a threaded sleeve, 16, adapted to bescrewed onto the ferrule, 10, and on the outer edge of the sleeve, 16,is arranged a clamping disk, 17, which is integrally connected to thesleeve, 16, and spaced therefrom by means of connecting tongues orstrips, 18, as shown. In the disk, 17, is formed a centrally-disposedaperture, 19, through which the projecting outer end of the terminal pinextends when the cap is in a retracted or operative position. By meansof a cap constructed as herein shown and described, the end of theelectric terminal may be readily engaged with and disengaged from theprojecting end of the binding pin by drawing the cap outwardly againstthe tension of the spring, 13, until the clamping plate, 17, is beyondthe end of the binding pin, at which time the end of the terminal isslipped over the pin and the cap released to permit the spring toretract the same and hold the clamping plate in firm engagement with theterminal.

in forming the cap, the inner portion or sleeve, 10, thereof ispreferably formed from a straight strip or blank of metal in which thescrew threads are pressed and after which the inner edge is turned inand the blank bent in circular shape to form the ferrule, 10. The outerportion of the cap is also formed from a blank, cut or punched in theshape shown in Fig. 5 of the drawings, which is bent into shape to formthe sleeve portion 16, the clamping plate 17, and connecting tongues,18. The outer portion of the cap when thus formed is adapted to bescrewed onto the inner or sleeve portion of the cap, and by screwingsaid outer portion onto the sleeve port-ion to a greater or less degree,the tension of the spring, 13, may be regulated to clamp the disk, 17,into more or less tight engagement with the end of the electricterminal.

From the foregoing description, taken in connection with theaccompanying drawing, the construction and operation of the inventionmay be readily understood without requiring a more extended explanation.

Various changes in the form, proportion and the minor details ofconstruction may be resorted to without departing from the principle orsacrificing any of the advantages of the invention as defined in theappended claims.

Having thus described my invention, what I claim as new and desire tosecure by Letters-Patent, is:

l. A spark plug comprising a tubular body portion, an insulated bindingpin arranged in said body portion, a terminal fastening cap arranged onthe outer end of said plug, said cap comprising inner and outeradjustably connected sections, a clamping plate forming the outer end ofsaid cap, and a spring to hold said clamping plate in engagement withthe terminal of an electric conductor whereby said terminal is securedin electric contact with the end of said binding pin.

2. A spark plug comprising di-electrie body, a shoulder formed on theend thereof, a spring surrounding the body below the shoulder, a ferruleoverlying said spring, an electric sparking terminal member passingthrough said body, a cap surrounding the shouldered end of said body andadapted to hold a battery terminal on the sparking terminal and meansfor adjusting the connection between the cap and ferrule.

3. A sparking plug comprising a body of insulating material, a sparkingterminal passing therethrough and having a contacting surface, ashoulder on the end of the insulating body, a spring surrounding thebody beneath the shoulder, a ferrule surrounding the body and having aninturned flange adapted to engage one end of the spring, a capsurrounding the shoulder end of the body and having threads toadjustably engage the ferrule and a bridge piece extending across thecap and adapted to press a battery terminal into electrical engagementwith enlarged contacting surface of the sparking terminal.

In testimony whereof I have hereunto set my hand in presence of twosubscribing witnesses.

IRWIN FLOYD KEPLEB. Witnesses:

FRED J. STEINERT, H. E. KEPLER.

